Add support for Consul Peering

[remilapeyre]

No description provided.

[mkeeler]

Thanks for putting this PR up. There have been a few changes since the alpha which will necessitate some changes but overall, almost everythingin the PR looks correct to me.

[mkeeler]

hmm, so peering token create will behind the scenes create a peering that can be read or deleted. The read and delete functions should be able to reuse what you created for the consul_peering resource. Without support for deletions, you could not use the tf provider to manage peerings without leaking the accepting side of the peering relationship.

[remilapeyre]

Hi @mkeeler, I'm not sure what else could do here, there's support for deleting a peering connection at https://github.com/remilapeyre/terraform-provider-consul/blob/peering/consul/resource_consul_peering.go#L163-L173 but the Consul API does not provide a way to invalid a Peering token that has not yet been used to established a connection.

Support for doing this with the Consul API would be needed if we want to implement a meaningful Delete() for this resource.

[mkeeler]

It does work but the peering APIs are a bit asymmetrical:

➜  curl -X POST localhost:8500/v1/peering/token -d '{"PeerName": "foo"}'
{
    "PeeringToken": "eyJDQSI6bnVsbCwiU2VydmVyQWRkcmVzc2VzIjpbIjEyNy4wLjAuMTo4NTAyIl0sIlNlcnZlck5hbWUiOiJzZXJ2ZXIuZGMxLmNvbnN1bCIsIlBlZXJJRCI6IjRmZmJkMzljLWZkYzYtOThkOC1kMWE3LWU3MjM3ZTEyMjllOSIsIkVzdGFibGlzaG1lbnRTZWNyZXQiOiJmYTE0M2Y1MS1kNDU1LThiYWQtNWM5Yi0yMDFhZmY2NTk4YzQifQ=="
}

~
➜  curl localhost:8500/v1/peerings
[
    {
        "ID": "4ffbd39c-fdc6-98d8-d1a7-e7237e1229e9",
        "Name": "foo",
        "Partition": "default",
        "State": "PENDING",
        "ImportedServiceCount": 0,
        "ExportedServiceCount": 0,
        "CreateIndex": 18,
        "ModifyIndex": 18
    }
]

~
➜  curl -X DELETE localhost:8500/v1/peering/foo

~
➜  curl localhost:8500/v1/peerings
[]

Basically issuing a request to either POST /v1/peering/token or POST /v1/peering/establish will create a peering which can be deleted with a DELETE /v1/peering/<peer name>.

[mkeeler]

Similarly you can still read an individual peering that has a token generated for it but the stream is not yet established:

➜  curl localhost:8500/v1/peering/foo
{
    "ID": "947b29ca-8dcf-1d61-1da8-0defeda6e0f0",
    "Name": "foo",
    "Partition": "default",
    "State": "PENDING",
    "ImportedServiceCount": 0,
    "ExportedServiceCount": 0,
    "CreateIndex": 27,
    "ModifyIndex": 27
}

The PENDING state here indicates that the stream is not established.

[remilapeyre]

Hi @mkeeler, all should be good now.